Thanks for the warning that man. Whoever does that, for whatever reason, needs a good kicking at the very least 
Sounds like a great idea to me, wonder if VOSA would do you for no dog clip though.
Could attach padlock to dog clip chain.
can’t see why. AFAIK the requirement is just that a safety device is fitted, lots of 5th wheels don’t have dog clips anyway.
Not something I have had happen to me personally but every time I’m away from the truck I check my pin religiously in fact even if I had a break and never left the seat I still check just for peace of mind too many people out there that take entertainment out of other people’s misfortune
I’m a Stobbies driver it’s second nature, because my truck attracts all the bitter and twisted 
del949:
Sounds like a great idea to me, wonder if VOSA would do you for no dog clip though.
Could attach padlock to dog clip chain.can’t see why. AFAIK the requirement is just that a safety device is fitted, lots of 5th wheels don’t have dog clips anyway.
No they don’t mind it. Especially if your 5th wheel has the sprung L clip too. We keep the same trailers so a few of us do this to prevent this kind of thing. I keep 1 key on the unit keys and one in the unit itself. Top tip though is to take it off once a week, give it a good wiggle and a squirt of WD40. 
I also take it off when it all goes in for sevice. Just clip the original dog clip through the padlock so it doesn’t disappear 
Happened to a very good mate of mine, who worked out of Appleton Stobarts, IN SAINSBURYS AT WALTHAM CROSS! An ex employee caught on cctv. Guess who got suspended? A ■■■■■ trick 
happened to me once, ironically working for stobrats out of Appleton, in STOKE DEPOT! 
brain dead them clay heads 
Beware of the phantom pin puller, they are never seen and lurk around for the opportunity to pounce, a bit like the ■■■■■ who thought it would be funny to un clip my trailer plate so it would fall off.
Lucky I did my checks.
Overnight at Lymm truckstop.